This is the native 64-bit counter of valid CLP=0 (high-priority) cells received in the ingress direction of this channel before the traffic management entity acts on them. Unlike its two-part 32-bit split representation used by older management stations, this single Counter64 lets modern SNMPv2c/v3 tools read the full-precision pre-shaping ingress volume of protected traffic in one poll. An admin sizing incoming bandwidth for a high-traffic PVC would read this value directly rather than reconstructing it from separate high/low 32-bit counters.